/*
 * Copyright The Apache Software Foundation
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.hadoop.hbase.filter;

import java.io.IOException;
import java.util.List;

import org.apache.hadoop.hbase.Cell;
import org.apache.yetus.audience.InterfaceAudience;
import org.apache.hadoop.hbase.exceptions.DeserializationException;
import org.apache.hadoop.hbase.shaded.protobuf.ProtobufUtil;
import org.apache.hadoop.hbase.shaded.protobuf.generated.FilterProtos;
import org.apache.hbase.thirdparty.com.google.protobuf.InvalidProtocolBufferException;

/**
 * This is a Filter wrapper class which is used in the server side. Some filter
 * related hooks can be defined in this wrapper. The only way to create a
 * FilterWrapper instance is passing a client side Filter instance through
 * {@link org.apache.hadoop.hbase.client.Scan#getFilter()}.
 */
@InterfaceAudience.Private
final public class FilterWrapper extends Filter {
    Filter filter = null;

    public FilterWrapper(Filter filter) {
        if(null == filter) {
            // ensure the filter instance is not null
            throw new NullPointerException("Cannot create FilterWrapper with null Filter");
        }
        this.filter = filter;
    }

    /**
     * @return The filter serialized using pb
     */
    @Override
    public byte[] toByteArray() throws IOException {
        FilterProtos.FilterWrapper.Builder builder = FilterProtos.FilterWrapper.newBuilder();
        builder.setFilter(ProtobufUtil.toFilter(this.filter));
        return builder.build().toByteArray();
    }

    /**
     * @param pbBytes A pb serialized {@link FilterWrapper} instance
     * @return An instance of {@link FilterWrapper} made from <code>bytes</code>
     * @throws org.apache.hadoop.hbase.exceptions.DeserializationException
     * @see #toByteArray
     */
    public static FilterWrapper parseFrom(final byte[] pbBytes) throws DeserializationException {
        FilterProtos.FilterWrapper proto;
        try {
            proto = FilterProtos.FilterWrapper.parseFrom(pbBytes);
        } catch(InvalidProtocolBufferException e) {
            throw new DeserializationException(e);
        }
        try {
            return new FilterWrapper(ProtobufUtil.toFilter(proto.getFilter()));
        } catch(IOException ioe) {
            throw new DeserializationException(ioe);
        }
    }

    @Override
    public void reset() throws IOException {
        this.filter.reset();
    }

    @Override
    public boolean filterAllRemaining() throws IOException {
        return this.filter.filterAllRemaining();
    }

    @Override
    public boolean filterRow() throws IOException {
        return this.filter.filterRow();
    }

    @Override
    public Cell getNextCellHint(Cell currentCell) throws IOException {
        return this.filter.getNextCellHint(currentCell);
    }

    @Override
    public boolean filterRowKey(byte[] buffer, int offset, int length) throws IOException {
        // No call to this.
        if(filterAllRemaining())
            return true;
        return this.filter.filterRowKey(buffer, offset, length);
    }

    @Override
    public boolean filterRowKey(Cell cell) throws IOException {
        if(filterAllRemaining())
            return true;
        return this.filter.filterRowKey(cell);
    }

    @Deprecated
    @Override
    public ReturnCode filterKeyValue(final Cell c) throws IOException {
        return filterCell(c);
    }

    @Override
    public ReturnCode filterCell(final Cell c) throws IOException {
        return this.filter.filterCell(c);
    }

    @Override
    public Cell transformCell(Cell v) throws IOException {
        return this.filter.transformCell(v);
    }

    @Override
    public boolean hasFilterRow() {
        return this.filter.hasFilterRow();
    }

    @Override
    public void filterRowCells(List<Cell> kvs) throws IOException {
        filterRowCellsWithRet(kvs);
    }

    public enum FilterRowRetCode {
        NOT_CALLED, INCLUDE,     // corresponds to filter.filterRow() returning false
        EXCLUDE,     // corresponds to filter.filterRow() returning true
        INCLUDE_THIS_FAMILY  // exclude other families
    }

    public FilterRowRetCode filterRowCellsWithRet(List<Cell> kvs) throws IOException {
        //To fix HBASE-6429,
        //Filter with filterRow() returning true is incompatible with scan with limit
        //1. hasFilterRow() returns true, if either filterRow() or filterRow(kvs) is implemented.
        //2. filterRow() is merged with filterRow(kvs),
        //so that to make all those row related filtering stuff in the same function.
        this.filter.filterRowCells(kvs);
        if(!kvs.isEmpty()) {
            if(this.filter.filterRow()) {
                kvs.clear();
                return FilterRowRetCode.EXCLUDE;
            }
            return FilterRowRetCode.INCLUDE;
        }
        return FilterRowRetCode.NOT_CALLED;
    }

    @Override
    public boolean isFamilyEssential(byte[] name) throws IOException {
        return filter.isFamilyEssential(name);
    }

    /**
     * @param o the other filter to compare with
     * @return true if and only if the fields of the filter that are serialized
     * are equal to the corresponding fields in other.  Used for testing.
     */
    @Override
    boolean areSerializedFieldsEqual(Filter o) {
        if(o == this)
            return true;
        if(!(o instanceof FilterWrapper))
            return false;

        FilterWrapper other = (FilterWrapper) o;
        return this.filter.areSerializedFieldsEqual(other.filter);
    }
}
